RE: [PATCH 0/3] --end-of-options marker

From: Randall S. Becker <rsbecker@nexbridge.com>
Date: Aug 6, 2019, 16:36 UTC
Message-ID: <000f01d54c75$1a8fe460$4fafad20$@nexbridge.com>
In-Reply-To: <xmqqa7cml0s9.fsf@gitster-ct.c.googlers.com>

On August 6, 2019 12:25 PM, Junio wrote:

Show 19 quoted lines

> Jeff King <peff@peff.net> writes:
> 
> > It's hard for scripted uses of rev-list, etc, to avoid option
> > injection from untrusted arguments, because revision arguments must
> > come before any "--" separator. I.e.:
> >
> >   git rev-list "$revision" -- "$path"
> >
> > might mistake "$revision" for an option (with rev-list, that would
> > make it an error, but something like git-log would default to HEAD).
> 
> Just to make sure I understand what I just read, let me paraphrase.
> We would want to accept
> 
> 	git rev-list --max-parents=4 \
> 		--end-of-options \
> 		--count -- docs/
> 
> so that '--count' would go thru the usual "as we have -- later, it must be

a rev

> and we do not even disambiguate.  What does get_sha1() say it is?" and
> "docs/" would be taken as a pathspec.
> "git rev-list --max-parents=4 --count -- docs/" would have treated

"--count"

> as an option and would error out due to lack of any starting revision.
> 
> On the other hand, "git log --count -- docs/" would take "--count"
> as an option, but does not complain about lack of any revs.  It just

starts

Show 6 quoted lines

> digging from HEAD and ends up ignoring the "--count" branch (or is this
> feature meant to support tags?  As far as I recall, we do not allow branch
> names that begin with a dash).
> 
> > This series provides an alternative to "--" to stop option parsing
> > without indicating that further arguments are pathspecs.

Would this offer the opportunity to, in the long term, supply options to external diff engines, for example?

Something like git diff --end-of-options --diff-opt1 --diff-opt2 -- a b

I'm just noodling here, wondering why otherwise

git rev-list --max-parents=4  -- --count docs/

does not work. I thought -- was pretty specific in terms of turning off interpretation. So is it not a defect that --count is being interpreted?

I have a fear for all my sub-teams who script with the assumption that -- has a specific meaning of stopping interpretation.

Slightly confused, Randall

Show 12 quoted lines

> >
> >   [1/3]: revision: allow --end-of-options to end option parsing
> >   [2/3]: parse-options: allow --end-of-options as a synonym for "--"
> >   [3/3]: gitcli: document --end-of-options
> >
> >  Documentation/gitcli.txt | 6 ++++++
> >  parse-options.c          | 3 ++-
> >  revision.c               | 8 +++++++-
> >  t/t0040-parse-options.sh | 7 +++++++
> >  t/t4202-log.sh           | 7 +++++++
> >  t/t6000-rev-list-misc.sh | 8 ++++++++
> >  6 files changed, 37 insertions(+), 2 deletions(-)